Clinical results of a phase II study of sorafenib in patients (pts) with non-GIST sarcomas (CTEP study #7060)

10001

Background: Sorafenib, an oral multi-targeted tyrosine kinase inhibitor, approved for the treatment of renal carcinoma, inhibits tumor cell proliferation and angiogenesis. We performed a multi-institutional phase II trial of sorafenib in sarcoma. Methods: Six different histological categories were examined, each as a separate Simon two-stage trial. The starting dose of sorafenib was 400 mg PO BID. If ≥1 RECIST partial response (PR) was observed in the first 12 pts, 25 more were accrued to that arm. Results: 120 pts (40 M, 80 F) received 553 28-day cycles of therapy as of 1/07. Two RECIST PR were observed in 37 (6%) leiomyosarcoma (LMS) pts and at least 3 PR in 23 (13%) angiosarcomas (AS) pts. No PR were seen in pts with MFH, synovial sarcoma, malignant peripheral nerve sheath tumor (MPNST) or other sarcomas. Median time to progression (mTTP) is 10 ( ± 2), 15 ( ± 3), and 23 ( ± 4) weeks for non-AS, LMS and AS pts, respectively (Kaplan-Meier estimate,  ± SE). mTTP for AS is >2 fold longer than for other histologies (p=0.039, log rank), and compares favorably with single institution mTTP data for angiosarcoma (paclitaxel 17.3 wk, doxorubicin 16 wk, Fury et al. Cancer J. 2005; 11:241). 64/120 (53%) pts required dose reductions, mostly for dermatological toxicity (see abstract by Keohan, this meeting). Other grade 3, 4 and 5 toxicities included asthenia, hypertension, cardiomyopathy and hemorrhage. Two fatalities, from hemorrhage and intestinal perforation, were deemed possibly related to treatment. Correlative sorafenib pharmacokinetics, MAPK pathway activation and soluble markers of angiogenesis will be presented. Conclusions: Sorafenib has significant activity against angiosarcoma, although the RECIST response rate is low. Sorafenib is associated with disease control in other sarcoma subtypes (e.g. LMS). Accrual continues in AS and MPNST. Further study of sorafenib in sarcomas appears warranted, either in combination with cytotoxic chemotherapy or in a randomized setting. Supported in part by P01-CA47179 Sarcoma Program Project grant and N01 phase II grant.

[Table: see text]

Phase I trial of bortezomib and celecoxib in patients with advanced solid tumors

13051

Background: The ubiquitin-proteosome pathway plays an important role in cell cycle regulation, neoplastic growth, and metastasis. Nuclear factor-kB (NF-kB) is a key transcription factor in cancer, primarily regulated by proteosome-mediated degradation of the inhibitor protein I kappa B alpha-associated protein kinase (IkBa). Interruption of this degradative pathway, with the 26S proteosome inhibitor bortezomib, has displayed significant clinical anti-tumor activity, in multiple myeloma and lymphomas. The role of bortezomib in the treatment of advanced solid tumors, however, is unclear at present. Preclinical work in multiple myeloma cell lines has demonstrated synergy in cytotoxicity and growth inhibiton with the combination of bortezomib and the cyclooxygenase (COX)-2 inhibitors. We therefore hypothesized that the combination of the COX-2 inhibitor celecoxib and bortezomib is a potentially active combination in the treatment of advanced solid tumors. Towards this aim, we are conducting a phase I study to determine the maximum tolerated dose (MTD) and toxicity profile of bortezomib and celecoxib. Methods: Patients with advanced solid tumors and an ECOG PS of 0–2 received escalating doses of bortezomib (1.0–1.6 mg/m2), either weekly for 5 of 6 weeks or twice weekly for 2 of 3 weeks, and celecoxib (200–400 mg twice daily). Accrual was planned to a maximum of 6 cohorts, each with a minimum of 3 patients. Only those dose-limiting toxicities (DLTs) occurring during the first cycle were used to define the MTD. DLTs included any grade 4 hematologic toxicity related to therapy, or any grade 3 or 4 non-hematologic toxicity. Results: To date, 10 patients (median age of 63y) have been treated. Represented tumor types include stage IV: colorectal, pancreatic, bladder, leiomyosarcoma, head and neck squamous cell carcinoma, hepatocellular, and renal cell. A median number of 2 cycles were administered. Thus far, no DLTs have been observed. No cumulative toxicities have been noted. No objective tumor response has been observed, however, stable disease was maintained in one heavily pre-treated patient with metastatic papillary renal cell cancer for 5 months. Conclusions: The combination of bortezomib and celecoxib is safe and well tolerated, with no dose-limiting toxicities thus far.

[Table: see text]

[TrueFISP MR imaging to determine the influence of hemodialysis on the myocardial functional parameters in patients with terminal renal insufficiency]

PURPOSE

To assess the characteristic signs of uremic cardiomyopathy in patients with chronic renal failure (CRF) in comparison with healthy volunteers and to determine changes of left ventricular (LV) functional parameters in patients undergoing hemo-dialysis (HD).

METHODS AND MATERIALS

Using a 1.5 T Magnetom Sonata system (Siemens, Erlangen), cardiac MR imaging was performed on 26 patients (20 men, 6 women, mean age 54.7 years) and 14 volunteers (8 men, 6 women, mean age 27.7 years). Single-slice true FISP sequences (TR 3.2 ms, TE 1.6 ms, flip angel 58 degrees, matrix 256 x 208, slice thickness 5 mm) were used to obtain contiguous short axis slices covering the whole left ventricle. Patients were examined before and immediately after HD. Cardiodynamic parameters [end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), ejection fraction (EF), myocardial mass (MM), cardiac output (CO)] were calculated using the modified Simpson's rule (Argus Software, Siemens). Patient data were compared to reference values taken from healthy volunteers.

RESULTS

As a consequence of HD, significant differences (p < 0.01) were observed for EDV (150 + 47 ml/114 + 49 ml), ESV (71 + 46 ml/60 + 56 ml), SV (79 + 25 ml/57 + 27 ml) and CO (3.6 + 1.0 l/min*m (2)/2.6 + 1.1 l/min*m (2)). Although EF (56 + 15 %/53 + 18 %) was decreased after HD, values did not differ significantly (p > 0.05). MM (148 + 47 g/148 + 52 g) and myocardial mass index (80.7 +/- 27.4 g/m (2)/80.1 +/- 9.1 g/m (2)) did not change before and after HD. In all patients, signs of LV-hypertrophy (LVH) and increased CO were diagnosed compared to reference values. In 8 of 26 patients, additional pathology, such as valvular dysfunction or global cardiac insufficiency, was detected.

CONCLUSION

Cardiac MRI is an accurate tool to identify uremic cardiomyopathy in patients with chronic renal failure undergoing HD. LV functional parameters could be monitored reliably.

Realisation of the EU Directive 91/271/EWG in Germany technical and economic effects from the perspective of an operator of large wastewater treatment plants

In the Federal Republic of Germany, the requirements on the effluent quality which wastewater treatment plants (WWTPs) with a design value larger than 100,000 PE must achieve in regard to the parameter Nanorg were increased by a national regulation on 01/08/2002. The reason for this action was a pending threat of the European Court because of the insufficient realisation of the EU Municipal Wastewater Directive (91/271/EWG). The report at hand describes the consequences of such an increase of the requirements for operators of WWTPs, using the example of Emschergenossenschaft and Lippeverband. The currently applicable demands in Germany are compared to those valid on a European level, and the current construction and performance state of the WWTPs operated by Emschergenossenschaft and Lippeverband is presented. The secure compliance with the increased requirements necessitates optimisation measures, but also construction measures; these are described in regard to their technical realisation and the prospective costs.

[Multislice TrueFISP-MR imaging for identifying stress-induced myocardial functional disturbances in coronary heart disease]

PURPOSE

This study assesses the left ventricular function using a new multislice cine sequence and determines the diagnostic accuracy of stress-induced wall motion abnormalities in patients with coronary artery disease (CAD).

MATERIALS AND METHODS

15 patients (mean age 57.7 years) with angiographically proven CAD were examined on a 1.5 T whole body system (Magnetom Sonata, Siemens, Erlangen) at rest and during dipyridamole-induced (0.56 mg/kg body weight) stress. Left ventricular function was determined using a multislice (steady-state) sequence (TR 2.3 ms, TE 1.15 ms, slice thickness 10 mm, temporal resolution 77 ms) as well as a standard single-slice true FISP 2D sequence (TR 3.2 ms, TE 1.6 ms, slice thickness 5 mm, temporal resolution 45 ms) as reference.

RESULTS

Both cine sequences provide high sensitivity and excellent correlation (r = 0.95) with angiographic findings for the detection of regional wall motion abnormalities. However, the measurement of functional parameters yielded significant differences. End-systolic left ventricular volumes (ESV) were systematically overestimated in the multislice images (mean 78 ml, + 5.8 %) compared with the reference single-slice images (mean 74 ml) (p < 0.05). This resulted in underestimation of the ejection fraction with multislice images (mean 40 %, - 11.3 %) compared with single-slice images (mean 46 %) (p < 0.05).

CONCLUSION

The multislice sequence results in a substantial reduction of imaging time and breath-hold periods necessary to cover the left ventricle for functional assessment. The multislice sequence yields adequate images, especially for qualitative determination of wall motion abnormalities. Due to the reduced spatial and temporal resolution of the multi-slice sequence, however, some uncertainty concerning the functional parameters has to be taken into account.

Noncovalent interactions between tetrazole and an N,N'-diethyl-substituted benzamidine

Amidines have long been known to form strong noncovalent complexes with carboxylates and phosphates. However, their interaction with tetrazoles, which are acidic heterocycles and important bioisosteric replacements for carboxylic acids in medicinal chemistry, has remained unexplored so far. The binding of a tetrazole to an N,N'-diethyl-substituted benzamidine has been studied for the first time by X-ray crystallography, solution NMR methods, and electrospray mass spectrometry. The amidinium group of model complex 3 was found to prefer an E,Z configuration in the crystal. Benzamidinium and tetrazolate groups alternate along an infinite chain of hydrogen bonds and salt bridges between the amidine-NH groups and the two tetrazole-N atoms next to the ring carbon. In solution, a 1:1 complex was evident from Job's method of continuous variation, and an association constant of 4.0 x 10(3) +/- 1.6 x 10(3) M(-)(1) (in CDCl(3)/CD(3)CN, 6:1) could be determined by (1)H NMR dilution experiments. Tetrazolate was not only found to be a weaker ligand than carboxylates but, surprisingly, the binding mode also changed with concentration in neat CDCl(3). At low concentrations, the amidine group in complex 3 adapted an E,E configuration as it does in a related carboxylic acid complex 4. With increasing concentration, the E,Z isomer starts to predominate. A free activation enthalpy DeltaG(298)() of 64 +/- 1 kJ mol(-)(1) for the E,E to E,Z isomerization was determined by line shape analysis at different magnetic fields. Binding strength was further probed in a competition experiment between a bisamidine, a carboxylate, and a tetrazolate by electrospray mass spectrometry.

Phase II study of dolastatin-10 in patients with hormone-refractory metastatic prostate adenocarcinoma

Dolastatin-10 is a natural, cytotoxic peptide with microtubule-inhibitory and apoptotic effects. It has demonstrated in vitro and in vivo efficacy in the DU-145 human prostate cancer model. A Phase II clinical trial was designed in patients with hormone-refractory prostate cancer. Dolastatin-10 was administered at a dose of 400 microg/m2 i.v. every 3 weeks. Dose escalation to 450 microg/m2 was permitted. Toxicity evaluation was conducted every 2 weeks, and assessment of response was done at the end of every two cycles. Sixteen patients were enrolled between October 1998 to December 1999. The median age was 71 years (range, 59-79 years). Median prostate-specific antigen value was 108 ng/ml (range, 15.3-1672 ng/ml). Of the 15 eligible patients, 7 were Caucasian and 8 were African-American. Eight patients had bone-only metastases, and seven had measurable disease with or without bone metastases. A total of 56 cycles have been administered. Only 2 patients required dose adjustment because of toxicity, and in 5 patients, dose escalation was feasible to 450 microg/m2. The major toxicities observed were grade 3 and 4 neutropenia in 8 patients and grade 3 neuropathy in 1 patient. All 15 patients are evaluable for response. Three patients demonstrated stable disease; 2 of these had bone disease, and 1 had nodal metastasis. All others had disease progression. Dolastatin-10 is very well tolerated in this elderly, pretreated population but lacks significant clinical activity as a single agent.

Archaeal ribosomal protein L1: the structure provides new insights into RNA binding of the L1 protein family

BACKGROUND

L1 is an important primary rRNA-binding protein, as well as a translational repressor that binds mRNA. It was shown that L1 proteins from some bacteria and archaea are functionally interchangeable within the ribosome and in the repression of translation. The crystal structure of bacterial L1 from Thermus thermophilus (TthL1) has previously been determined.

RESULTS

We report here the first structure of a ribosomal protein from archaea, L1 from Methanococcus jannaschii (MjaL1). The overall shape of the two-domain molecule differs dramatically from that of its bacterial counterpart (TthL1) because of the different relative orientations of the domains. Two strictly conserved regions of the amino acid sequence, each belonging to one of the domains and positioned close to each other in the interdomain cavity of TthL1, are separated by about 25 A in MjaL1 owing to a significant opening of the structure. These regions are structurally highly conserved and are proposed to be the specific RNA-binding sites.

CONCLUSIONS

The unusually high RNA-binding affinity of MjaL1 might be explained by the exposure of its highly conserved regions. The open conformation of MjaL1 is strongly stabilized by nonconserved interdomain interactions and suggests that the closed conformations of L1 (as in TthL1) open upon RNA binding. Comparison of the two L1 protein structures reveals a high conformational variability of this ribosomal protein. Determination of the MjaL1 structure offers an additional variant for fitting the L1 protein into electron-density maps of the 50S ribosomal subunit.

Control of ribosomal protein L1 synthesis in mesophilic and thermophilic archaea

The mechanisms for the control of ribosomal protein synthesis have been characterized in detail in Eukarya and in Bacteria. In Archaea, only the regulation of the MvaL1 operon (encoding ribosomal proteins MvaL1, MvaL10, and MvaL12) of the mesophilic Methanococcus vannielii has been extensively investigated. As in Bacteria, regulation takes place at the level of translation. The regulator protein MvaL1 binds preferentially to its binding site on the 23S rRNA, and, when in excess, binds to the regulatory target site on its mRNA and thus inhibits translation of all three cistrons of the operon. The regulatory binding site on the mRNA, a structural mimic of the respective binding site on the 23S rRNA, is located within the structural gene about 30 nucleotides downstream of the ATG start codon. MvaL1 blocks a step before or at the formation of the first peptide bond of MvaL1. Here we demonstrate that a similar regulatory mechanism exists in the thermophilic M. thermolithotrophicus and M. jannaschii. The L1 gene is cotranscribed together with the L10 and L11 gene, in all genera of the Euryarchaeota branch of the Archaea studied so far. A potential regulatory L1 binding site located within the structural gene, as in Methanococcus, was found in Methanobacterium thermoautotrophicum and in Pyrococcus horikoshii. In contrast, in Archaeoglobus fulgidus a typical L1 binding site is located in the untranslated leader of the L1 gene as described for the halophilic Archaea. In Sulfolobus, a member of the Crenarchaeota, the L1 gene is part of a long transcript (encoding SecE, NusG, L11, L1, L10, L12). A previously suggested regulatory L1 target site located within the L11 structural gene could not be confirmed as an L1 binding site.

The PIM-1 serine kinase prolongs survival and inhibits apoptosis-related mitochondrial dysfunction in part through a bcl-2-dependent pathway

We have examined potential mechanisms by which the Pim-1 kinase acts as a hematopoietic cell survival factor. Enforced expression of the wild type 33 kd (FD/hpim33) and 44 kd (FD/mpim44) Pim-1 proteins in murine factor-dependent FDCP1 cells prolonged survival after withdrawal of IL-3, while expression of a dominant negative Pim-1 protein (FD/pimNT81) shortened survival. Following removal of IL-3 FDCP1 cells exhibited loss of mitochondrial transmembrane potential and production of reactive oxygen species, as determined by flow cytometry analysis. The wild type Pim-1 proteins decreased these changes while the dominant negative protein enhanced mitochondrial dysfunction. The antiapoptotic activity of the kinases could not be attributed to modulation of glutathione, catalase, or superoxide dismutase activities. Both the FD/hpim33 and FD/mpim44 cells maintained expression of bcl-2 mRNA following cytokine removal, while a substantial decrease was seen in FD/neo cells. To modulate Bcl-2 protein levels, a bcl-2 antisense RNA construct was coexpressed with the wild type pim-1 cDNAs. FD/hpim33 cells with low cellular Bcl-2 protein levels had shortened cytokine-independent survival compared with FD/hpim33 clones with high Bcl-2 expression. However survival of FD/mpim44 cells after IL-3 withdrawal was substantially independent of cellular Bcl-2 protein levels. The 33 kd protein delayed, and the 44 kd protein completely prevented enhanced cell death associated with enforced expression of human Bax protein however. Our results suggest that the 33 kd Pim-1 kinase may enhance cell survival through cooperation with and regulation of bcl-2. In addition the 44 kd kinase may regulate the expression or activity of other pro- and anti-apoptotic members of the bcl-2 family.

Imaging of a metastatic gastrointestinal carcinoid by F-18-DOPA positron emission tomography

The localization of carcinoids in the gastrointestinal tract is frequently difficult if not impossible with the imaging procedures used to date. It is reported on a patient with metastasizing carcinoid in whom various imaging procedures were not successful in detecting the primary tumor. Due to the importance of primary tumor proof for potential curative surgical therapy, a whole-body positron emission tomography with F-18-DOPA was performed. PET enabled localization of a potential primary tumor in the ileum. Moreover, in addition to the known abdominal lymph node and liver metastases, it detected a mediastinal lymph node metastasis and a pulmonary metastasis. F-18-DOPA whole-body PET may be a very promising imaging approach to the localization and staging of gastrointestinal carcinoids.

Responses of the soil microbiota to elevated CO2 in an artificial tropical ecosystem

Plants in artificial tropical ecosystems were grown under ambient (340 microl l(-1)) and elevated (610 microl l(-1)) atmospheric CO2 for 530 d under low-nutrient conditions on a substrate free of organic C. At the end of the experiment a number of soil chemical and microbiological variables were determined. Although we found no changes in total soil organic matter under elevated CO2, we did find that after physical fractionation the amount of organic C in the supernatant (< 0.2 microm) and the amount of water extractable organic C (WEOC) was lower under elevated CO2. The extractable optical density (OD) indicated a higher degree of humification for the elevated than for the ambient CO2 samples (P = 0.032). Microbial biomass C was not significantly altered under high CO2, but total bacterial counts were significantly higher. The microbial biomass C-to-N ratio was also higher at elevated (15.0) than at ambient CO2 (10.0). The number of mycorrhizal spores was lower at high CO2, but ergosterol contents and fungal hyphal lengths were not significantly affected. Changes were found neither in community level physiological profiles (CLPPs) nor in the structural attributes (phospholipid fatty acids, PLFAs) of the microbial community. Overall, the effects on the soil microbiota were small, perhaps as a result of the low nutrient supply and low organic matter content of the soil used in our study. The few significant results showing changes in specific, though relatively minor, organic matter pools may point to possible long-term changes of the more major pools. Furthermore, the data suggest increased competition between plants and microbes for N at high CO2.

Vascular endothelial growth factor in the sera and effusions of patients with malignant and nonmalignant disease

BACKGROUND

Clinical data clearly indicate a correlation between tumor neovascularization, aggressiveness of tumor growth, and metastatic spread. One of the key factors capable of stimulating tumor angiogenesis is vascular endothelial growth factor (VEGF). Using an immunoassay for VEGF, we assessed the levels of soluble VEGF in the sera and effusions of patients with malignant and nonmalignant disease as well as in the sera of healthy controls.

METHODS

Using a sandwich enzyme-linked immunoadsorbent assay, the concentration of VEGF was measured in serum specimens (n=445) and effusions (n=56) collected from a total of 212 patients with various types of cancer, 88 patients with nonmalignant disease, and 145 healthy individuals.

RESULTS

Low and rather stable levels of VEGF were detected in the serum of healthy individuals (median, 294 pg/mL; range, 30-1752 pg/mL; 95th percentile, 883 pg/mL). Compared with healthy individuals, serum levels in patients with acute infections were elevated (P=0.03), whereas patients with chronic cirrhosis had lower serum VEGF levels. Among patients with various types of neoplasia, VEGF serum levels in patients with ovarian or gastrointestinal carcinoma were significantly higher than in healthy individuals. Moreover, VEGF concentrations in sera from patients with metastatic disease were higher than in sera from patients with localized tumors. Maximum serum concentrations of VEGF (median, 1022 pg/mL; range, 349-7821 pg/mL) were found in patients with metastatic ovarian carcinoma. Median VEGF levels (and ranges) in malignant effusions were up to 10-fold higher than in matched serum samples: 5528 pg/mL (468-49269 pg/mL) in ovarian carcinoma, 885 pg/mL (77-14,337 pg/mL) in breast carcinoma, and 813 pg/mL (372-18,331 pg/mL) in gastrointestinal carcinoma. In contrast, ascitic fluid from patients with cirrhosis contained only 303 pg/mL (median, range 116-676 pg/mL) of VEGF, corresponding to the low serum levels in this patient group.

CONCLUSIONS

Depending on the tumor type, elevated levels of VEGF are detectable in the serum of only 0-20% of patients with localized cancer but in 11-65% of patients with metastatic cancer. Of cytology-proven malignant ascites or peritoneal exudates from various malignancies, 46-96% show VEGF levels above the upper limit (95th percentile, 676 pg/mL) of nonmalignant ascites. Maximum VEGF concentrations in malignant effusions indicate abundant local release of VEGF within the pleural or peritoneal cavity. These results suggest that VEGF might play an important role in tumor progression and the formation of malignant effusions. Further studies are warranted to determine the clinical value of soluble VEGF as a tumor marker, a prognostic factor, and a surrogate indicator of tumor angiogenesis.

Vascular endothelial growth factor in the sera and effusions of patients with malignant and nonmalignant disease

BACKGROUND

Clinical data clearly indicate a correlation between tumor neovascularization, aggressiveness of tumor growth, and metastatic spread. One of the key factors capable of stimulating tumor angiogenesis is vascular endothelial growth factor (VEGF). Using an immunoassay for VEGF, we assessed the levels of soluble VEGF in the sera and effusions of patients with malignant and nonmalignant disease as well as in the sera of healthy controls.

METHODS

Using a sandwich enzyme-linked immunoadsorbent assay, the concentration of VEGF was measured in serum specimens (n=445) and effusions (n=56) collected from a total of 212 patients with various types of cancer, 88 patients with nonmalignant disease, and 145 healthy individuals.

RESULTS

Low and rather stable levels of VEGF were detected in the serum of healthy individuals (median, 294 pg/mL; range, 30-1752 pg/mL; 95th percentile, 883 pg/mL). Compared with healthy individuals, serum levels in patients with acute infections were elevated (P=0.03), whereas patients with chronic cirrhosis had lower serum VEGF levels. Among patients with various types of neoplasia, VEGF serum levels in patients with ovarian or gastrointestinal carcinoma were significantly higher than in healthy individuals. Moreover, VEGF concentrations in sera from patients with metastatic disease were higher than in sera from patients with localized tumors. Maximum serum concentrations of VEGF (median, 1022 pg/mL; range, 349-7821 pg/mL) were found in patients with metastatic ovarian carcinoma. Median VEGF levels (and ranges) in malignant effusions were up to 10-fold higher than in matched serum samples: 5528 pg/mL (468-49269 pg/mL) in ovarian carcinoma, 885 pg/mL (77-14,337 pg/mL) in breast carcinoma, and 813 pg/mL (372-18,331 pg/mL) in gastrointestinal carcinoma. In contrast, ascitic fluid from patients with cirrhosis contained only 303 pg/mL (median, range 116-676 pg/mL) of VEGF, corresponding to the low serum levels in this patient group.

CONCLUSIONS

Depending on the tumor type, elevated levels of VEGF are detectable in the serum of only 0-20% of patients with localized cancer but in 11-65% of patients with metastatic cancer. Of cytology-proven malignant ascites or peritoneal exudates from various malignancies, 46-96% show VEGF levels above the upper limit (95th percentile, 676 pg/mL) of nonmalignant ascites. Maximum VEGF concentrations in malignant effusions indicate abundant local release of VEGF within the pleural or peritoneal cavity. These results suggest that VEGF might play an important role in tumor progression and the formation of malignant effusions. Further studies are warranted to determine the clinical value of soluble VEGF as a tumor marker, a prognostic factor, and a surrogate indicator of tumor angiogenesis.